XDR TB occurs when a Mycobacterium tuberculosis strain is resistant to isoniazid and rifampin, two of the most powerful first-line drugs, as well as key drugs of the second line regimen—any fluoroquinolone and at least one of the three injectable drugs shown above. XDR TB strains may also be resistant to additional drugs, greatly complicating therapy.
Photo Credit: The photo of Mycobacterium tuberculosis was obtained from the Centers for Disease Control and Prevention, CDC/ Dr. Ray Butler; Janice Carr.Illustration Credit: This illustration is in the public domain. Please credit the National Institute of Allergy and Infectious Diseases (NIAID). Illustrator: Krista Townsend
Last Updated May 17, 2007